Port Engine Cutting out

[jayj123]

I have 1985 model 270 Crusaders. The problem is at 2800 rpms, the port engine cuts out and drops to about 22 - 2300 and runs rough. This appears to be the point where the secondaries begin to open. Once I throttle back a little I can get back to 2800. The engine ran fine up to 3400 rpm the last time I ran it. Also, it appears to be running fine up to 2800 as I ran all day on both engines and had the same fuel burn for both. Any Ideas???

 

[makomark]

Doubt your secondaries are open below 3000 rpm.

If the fuel burn is consistent, I'd guess the ignition is fine and the issue is with a fuel restriction - valve not open, filter clogged, filter not seated well and leaking air....anti-syphon valves know to restrict fuel flow, too.